This invention relates to an invasive instrument for treating vessels and to a method.
It is known to harvest the endogenous vessels used for a bypass, i.e. veins and arteries, by an invasive, frequently also minimally invasive method under endoscopic control. This method is called Endoscopic Vessel Harvesting (EVH). In this method, especially developed instruments are employed.
Before the actual vessel harvesting takes place, the vessel must be separated from the tissue enclosing the vessel. First, an access is created by means of a small cut in direct vicinity of the vessel to be harvested, for example for harvesting the Vena saphena magna in the region of the knee-joint gap. Subsequently, the introduction of a suitably shaped instrument and the stepwise separation (dissection) by advancing along the vessel axis are effected under visual control and/or endoscopic view.
The known instruments can be used e.g. with an endoscope and/or a camera. From the patent specification U.S. Pat. No. 6,042,538 it is known that an endoscope optics can be integrated into the instrument. The instrument can be formed both as disposable and as reusable product. In a reusable product, the endoscope optics also can inseparably be integrated into the instrument.
Corresponding to the prior art, the endoscope which frequently is integrated into the instrument is connected with a video camera, so that the treating physician can observe his actions on a screen.
From the patent specification U.S. Pat. No. 5,928,138 it is known that a tip can be fabricated of a visually transparent material, so that during the dissection a good forward visibility is ensured for the operating surgeon via the endoscope. Such a transparent tip also is referred to as optical dissector.
The vessel to be harvested is connected with further, smaller peripheral vessels and after dissection from the surrounding tissue must also be separated from said vessels.
According to the prior art, this is effected by cutting devices integrated into the instrument. From the patent specification U.S. Pat. No. 6,022,313 it is known that such cutting device can be designed e.g. with scissors, which are advanced in a working channel of the instrument.
From the patent specification U.S. Pat. Nos. 5,928,138 and 6,022,313 it is known that devices for guiding the vessel to be harvested can be integrated into the instrument.
From the patent specification U.S. Pat. No. 7,645,289 it is known that a transparent tip can be shifted along the longitudinal axis of the instrument by means of a manipulator integrated at the handle. In addition, it is known from the patent specification U.S. Pat. No. 7,645,289 that the side of the tip facing the instrument is provided with a cutout. The design of the cutout allows the accommodation and/or fixation of the peripheral vessels to be separated.
It is furthermore known to support the endoscopically assisted vessel harvesting by means of CO2 gas insufflation. It is known that CO2 gas can selectively be introduced into the body through cavities and/or channels of an instrument for endoscopic procedures.